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BIBTEX RIS

Insecticide resistance of corn weevil populations from semi-arid regions

2018; Southern Cross Publishing; Volume: 12; Issue: 03 Linguagem: Inglês

10.21475/ajcs.18.12.03.pne863

ISSN

1835-2693

Autores

João Luciano de Andrade Melo, José Alexandre da Silva Júnior, Kleber Régis Santoro, César Auguste Badji,

Tópico(s)

Entomopathogenic Microorganisms in Pest Control

Resumo

Corn weevil (Sitophilus zeamais) is a key insect pest of stored corn in Brazil.Corn weevil infestations are traditionally controlled using insecticides.The intensive use of insecticidal compounds, however, may result in the development of insecticide-resistant populations and ultimately cause insecticide-based control measures to fail.The objective of the present work is to define the permethrin and pirimiphos-methyl resistance of S. zeamais populations collected from the semi-arid region of Pernambuco, Brazil.Insects were placed in glass bottles impregnated with dry insecticide residues at different concentrations.Deceased insects were counted 24 h after exposure.Concentration-response curves were generated by subjecting mortality results to Probit analysis.The Sete Lagoas population exhibited the lowest 50% mortality (LC 50 ) to permethrin, whereas the Lajedo population exhibited the lowest LC 50 to pirimiphos-methyl.These populations were used the reference peremthrin-and pirimiphos-methyl-susceptible populations.The order of the LC 50 -based susceptibility of the populations to the two insecticides differed from that of the LC 95based susceptibility.Six and eight populations showed a significant resistance ratio (RR 50 ) against permethrin and pirimiphosmethyl, respectively.The Brejão population presented the maximum resistance to pirimiphos-methyl (RR 50 = 26.7 and RR 95 = 57.4).All populations exhibited low but greatly varied pyrethroid resistance levels.This result, however, does not imply that the problem of pyrethroid resistance is minimized when resistance is substantial in the Brejão population.

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